1. Field of the Invention
This invention generally relates to temporary, portable road markers and, more particularly, to collapsible road markers and apparatus and methods for releasibly locking them in a collapsed state, for mounting reflector members to enhance visibility and for enhancing resistance against wind forces.
2. Description of the related art including information disclosed under 37 CFR 1.97-1.99
Collapsible road markers are known which enable a conical road marker body to be collapsed into a base for storage and transport.
In U.S Pat. No. 3,520,235 issued Jul. 14, 1970 to Palazzolo et al. a collapsible road marker is formed of tepee-like structure with a flexible conical sheet of plastic or other flexible sheet material which is supported in an erect position by means of a two piece center support pole which disassembles for storage in a base. This design is intended for personal use to warn traffic away from an automobile during an emergency road side repair, or the like. However, it is not well suited for use as a temporary marker for exterior local repairs where thousands of markers need to be moved on a regular basis and which are used continuously under the most harsh wind conditions. The central support pole disables the marker from being quickly collapsed or erected which is necessary when dealing with thousands of units, while the solid plastic or other outer body presents a large horizontal surface area making the marker susceptible to tipping due to wind forces and which is insufficiently durable for long continuous wear.
Subsequent designs are shown in U.S. Pat. Nos. 4,197,807 issued Apr. 15, 1980, to Campbell and 4,256,050 issued Mar. 17, 1981, to Barnard which employ a spiral body that collapses into a flat coil which is contained in a generally planar base when not in use. While these collapsible coils are better suited for regular traffic control applications, they still suffer from some of the same problems as the marker of Palazzolo et al. The spiral body of Barnard is closed throughout the length of its body making it highly vulnerable to wind forces. While the marker of Campbell is somewhat improved, since incidentally to the design, some air passageways are provided adjacent the base. However, the portions of the marker adjacent its top at which the moment arm for tipping forces is greatest, have no wind passageways passing straight through the body as needed for optimum stability in high wind.
Another problem with these known spiral arms collapsible is the lack of any means for easily and quickly locking the collapsible body in the collapsed position, so it does not undesirably deploy into an erect position during transportation, handling or storage. In the road marker of Barnard, the spiral arms are not resiliently biased toward the erect conical shape, and no separate locking mechanism is provided to prevent inadvertent deployment. A locking mechanism is provided in the marker of Campbell to hold the resilient spiral body in a flat coil configuration, but it employs an awkward wing nut which must be manually passed entirely through a slot while the coil is held in the collapsed condition and then manually forced to a locked position. Likewise, when unlocking the spiral body, the wing nut must be manually aligned to an unlocking position.
Another disadvantage of these collapsible road markers is the failure to provide a single means to releasibly attach reflective members to enhance night time visibility. In the marker of Palazzolo et al., the plastic cover is brightly colored and luminous, and no means are provided for the addition of additional reflective members. In each of the markers of Barnard and Campbell, reflective strips are attached along the lengths of the arms only, so that only horizontal reflective pattern are created. The reflective surfaces only face outwardly and thus substantial amounts of reflective material is required to achieve the desired visibility. However, there is no means for mounting additional reflector members. In addition, the reflective surfaces only face outwardly or are otherwise blocked from viewing from the inside or opposite side of the collapsible body.